History of Thrissur
| Timeline of Thrissur | |
| Year | Event |
| 1200 BCE – 200 CE | Iron Age Megalithic Culture |
| 2nd–1st century BCE | Rise of Muziris as a port |
| 1st–3rd centuries CE | Roman coins of the period found |
| 800–1124 | Rule of Perumals of Mahodayapuram |
| 855 | Sthanu Ravi inscription at Koodalmanikyam Temple at Irinjalakuda |
| 930 | Kota Ravi inscriptions at Avittathur |
| 1000 | Jewish Copper plate issued at Mahodayapuram |
| 1024 | Rajasimha inscription at Thazhekad |
| 1036 | Rajasimha inscription at Thiruvanchikulam Temple |
| 11th century | Inscription at Vadakkumnathan Temple, Thrissur |
| 1225 | Syrian Christian copper plate issued by Vira Raghava of Perumpadapu Swaroopam |
| 1523 | Portuguese Fort at Cranganore |
| 1599 | Syrian Christian priests from Palayoor and Mattom take part in the Synod of Diamper |
| 1606, 1677, 1681 | Inscriptions at Palayoor |
| 1710 | Dutch control over Chettuva |
| 1750–1762 | Zamorin's occupation of Thrissur |
| 1789 | Tipu Sultan's occupation of Thrissur |
| 1790–1805 | Rule of Rama Varma, Sakthan Thampuran |
| 1791 | Treaty between Cochin and the East India Company by which Kingdom of Cochin became a vassal of the company |
| 1794 | Fortifications around the Thrissur town by Sakthan Thampuran |
| 1800 | Cochin State placed under the Madras Government |
| 1814 | Construction of the Mart Mariam Big Church at Thrissur |
| 1816 | The first known map of Thrissur prepared by John Gould |
| 1889 | St. Thomas College, Thrissur founded |
| 1921 | Thrissur made a municipality |
| 1925 | Cochin Legislative Council with elected members from Thrissur |
| 1925, 1927 | Mohandas Karamchand Gandhi visits Thrissur |
| 1935 | Labour Brotherhood in Thrissur |
| 1936 | Cochin State Congress founded |
| 1936 | Electricity agitation |
| 1940 | Cochin Karshakasabha founded |
| 1941 | Cochin State Prajamandal |
| 1947 | Temple entry allowed in Cochin |
| 1949 | Travancore-Cochin State comes into existence |
| 1 July 1949 | Thrissur district was formed |
| 1956 | Formation of Kerala State |
Thrissur is the administrative capital of Thrissur District, in the central part of Kerala state, India. Thrissur district was formed on 1 July 1949. It is an important cultural centre, and is known as the Cultural Capital of Kerala. It is famous for the Thrissur Pooram festival, one of the most colourful and spectacular temple festival of Kerala. From ancient times, Thrissur has been politically, economically and culturally significant to the Indian subcontinent. It has opened the gates for Arabs, Romans, Portuguese, Dutch and English. According to tradition, Thrissur is where Christianity, Islam and Judaism entered the Indian subcontinent. Local Christian tradition holds that Thomas the Apostle arrived in 52 CE, and Muslim tradition states that Methala is the location of country's first mosque.